Husqvarna TC449 Workshop Manual page 307

ELECTRICAL SYSTEM
The ignition system is controlled by the ECU (1). The ignition is an integrated
digital electronic ignition system with static timing and advance using intermit-
tent sequential phased electronic injection feed. This ignition system is com-
posed of a crankshaft position (pick-up) sensor (2), an ECU (1), an ignition coil
(3) and an intake manifold pressure sensor (5). The ignition coil is fed by the
battery through a power relay and is controlled by the ECU. Ignition timing is
accurately determined based on engine RPM and accelerator position. In ad-
dition to these key parameters, inputs from the intake air temperature (4) and
pressure (5) sensors and from the coolant temperature sensor are also used
to control ignition timing.
Key
1. ECU
2. Crankshaft position sensor
3. Ignition coil
4. Intake air temperature sensors
5. Pressure sensor
6. Coolant temperature sensor
1 edition (08-2010)_Rev. 11-2010 M.27
st